Multi-piece machine tool base

ABSTRACT

A power tool having a base assembly with a first portion, which defines an upper surface, and a second portion that defines a lower surface. The first and second portions may be castings and are coupled to one another without machining the upper surface of the first portion or the lower surface of the second portion. After assembly of the base portion, the upper surface of the second portion is machined to define a flat reference surface. Construction of the power tool in this manner provides a robust base assembly that is relatively inexpensive to manufacture. A related method is also provided.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. patent applicationSer. No. 10/731,792 filed Dec. 9, 2003, which is a divisionalapplication of U.S. patent application Ser. No. 10/124,746 filed Apr.17, 2002 (now U.S. Pat. No. 6,601,621 issued Aug. 5, 2003), which claimspriority to U.S. Provisional Application Ser. No. 60/284,486 filed onApr. 18, 2001, entitled “Portable Power Planer”.

FIELD OF THE INVENTION

The present invention generally relates improvements in portable powertools, and more specifically to improvements that are particularly wellsuited for use with wood working power tools such as portable powerplaners.

BACKGROUND OF THE INVENTION

Various power tools are used in woodworking in an effort to efficientlyand accurately form workpieces to desired dimensions and with a desiredsurface finish. As is widely known, planing machines are often used forsurface planing of wooden boards. A conventional planing machinetypically includes one or more rotatably mounted cutting blades attachedto a vertically movable carriage assembly. Also known are jointermachines which are typically used for the edge planing of wood. Incertain applications, the functions of conventional planing machines andjointers are combined within a single unit commonly referred to as ajointer/planer machine.

In a typical wood planing machine, such as a surface planer, aselectively adjustable workpiece opening is defined between a carriageassembly and the planing surface of the base of the machine. Therotationally mounted blades are carried on the underside of the carriageassembly adjacent to the workpiece opening. The blades are adapted toremove a predetermined amount of material from the workpiece dependingon the thickness of the workpiece and the height of the workpieceopening. The carriage assembly also usually includes one or more feedrollers which urge the workpiece through the workpiece opening duringthe operation of the wood planing machine.

In most applications, the carriage assembly of a wood planing machine ismovably mounted to a plurality of support columns for movement withrespect to the planing surface. Such movement of the carriage assemblyadjusts the vertical dimension of the workpiece opening so as toselectively determine the amount of material to be removed from theworkpiece. Alternatively, the carriage assembly may be fixed and theplaning surface adjusted vertically with respect to the carriageassembly so as to adjust the vertical dimension of the workpieceopening.

In use, a workpiece is passed through the workpiece opening and apredetermined amount of material is removed from the surface of theworkpiece adjacent the carriage assembly. Multiple passes of theworkpiece through the workpiece opening are often necessary to obtainthe desired thickness and surface finish. As with other woodworkingoperations, it is desirable that a planing machine accomplishespreparation with precision, repeatability and a high quality surfacefinish. In order to accomplish these goals, many of the planing machinesof the prior art have relied on designs that utilize rather large andheavy components.

While such designs have proven to be acceptable for relatively largeplaning machines which are repositioned on a relatively infrequentbasis, they have largely been inadequate for portable planing machines,due to their weight. Accordingly, there is a need in the art for aportable planing machine having a highly robust design that permits aworkpiece to be prepared with precision, repeatability and a highquality surface finish.

SUMMARY OF THE INVENTION

In one form, the present teachings provide a method comprising: forminga base structure with a body portion that defines a support surface;forming a plate structure; coupling the plate structure to the basestructure; and machining the plate structure to define a flat referencesurface only after the plate structure and the base structure have beencoupled to one another; wherein the support surface is not machinedprior to the coupling of the plate structure and the base structure.

Further areas of applicability of the present invention will becomeapparent from the detailed description provided hereinafter. It shouldbe understood that the detailed description and specific examples, whileindicating the preferred embodiment of the invention, are intended forpurposes of illustration only and are not intended to limit the scope ofthe invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Additional advantages and features of the present invention will becomeapparent from the subsequent description and the appended claims, takenin conjunction with the accompanying drawings, wherein:

FIG. 1 is a perspective view of a portable power planer constructed inaccordance with the teachings of the present invention;

FIG. 2 is an exploded perspective view of the portable power planer ofFIG. 1;

FIG. 3 is an exploded perspective view of a portion of the portablepower planer of FIG. 1 illustrating the planer carriage assembly ingreater detail;

FIG. 3 a is a side view of a portion of the portable power planer ofFIG. 1 illustrating a portion of the motor shaft in greater detail;

FIG. 3 b is an enlarged portion of FIG. 3 illustrating the motorassembly in greater detail;

FIG. 4 is an exploded perspective view of a portion of the portableplaner mechanism of FIG. 1, illustrating the gearbox and the powertake-off mechanism in greater detail;

FIG. 4 a is a sectional view illustrating a portion of the finalreduction gear;

FIG. 4 b is a sectional view illustrating the connection between thehandle, the first axle and the support plate;

FIG. 5 is an exploded perspective view of a portion of the portableplaner mechanism of FIG. 1, illustrating the base assembly in greaterdetail;

FIG. 6 is a sectional view taken along the line 6-6 of FIG. 5;

FIG. 7 is a sectional view similar to that of FIG. 6 but illustrating abase assembly constructed in accordance with an alternate embodiment ofthe present invention;

FIG. 8 is an exploded perspective view of a portion of the portableplaner mechanism of FIG. 1, illustrating the planer carriage elevationmechanism in greater detail;

FIG. 9 is a sectional view taken along the line 9-9 of FIG. 1;

FIG. 10 is a partially broken-away perspective view illustrating aplaner carriage elevation mechanism constructed in accordance with analternate embodiment of the present invention;

FIG. 11 is a perspective view illustrating the bottom surface of theupper cam in greater detail;

FIG. 12 is a side view illustrating the upper and lower cams in theneutral position;

FIG. 13 is a side view illustrating the upper and lower cams in thelocked position;

FIG. 14 is an exploded perspective view of a portion of the portableplaner mechanism of FIG. 1, illustrating the cutter head assembly ingreater detail;

FIG. 15 is an exploded perspective view of a cutter head assemblyconstructed in accordance with an alternate embodiment of the presentinvention;

FIG. 16 is a section view taken along the line 16-16 of FIG. 15;

FIG. 17 is a sectional view of the portable planer mechanism of FIG. 15illustrating the release levers and the lever locks;

FIG. 18 is a sectional view similar to that of FIG. 16 but illustratingthe release levers in the engaged position;

FIG. 19 is an exploded perspective view of a portion of the portableplaner mechanism of FIG. 1, illustrating the carriage height settingmechanism in greater detail;

FIG. 20 is a side view of the rotary selector knob;

FIG. 21 is a partial sectional view of the portable planer mechanismtaken through the longitudinal axis of the stop member;

FIG. 21 a is a view similar to that of FIG. 19 but showing analternately constructed carriage height setting mechanism;

FIG. 22 is an exploded perspective view of a portion of the portableplaner mechanism of FIG. 1, illustrating the height scale mechanism ingreater detail;

FIG. 23 is an enlarged perspective view of a portion of the height scalemechanism illustrating the coupling of the wire member to the baseassembly;

FIG. 24 is an enlarged perspective view of a portion of the height scalemechanism illustrating the operation of the rotary scale;

FIG. 25 is a rear view of the tension wheel;

FIG. 25 a is a view similar to FIG. 22 but illustrating an alternatelyconstructed height scale mechanism;

FIG. 26 is an exploded perspective view of a portion of the portableplaner mechanism of FIG. 1, illustrating the material removal gauge;

FIG. 27 is a cross-sectional view taken along the line 27-27 of FIG. 1;

FIG. 28 is a sectional view illustrating an exemplary pointer that doesnot provide a magnification effect;

FIG. 29 is a sectional view illustrating an exemplary pointer thatprovides a magnification effect;

FIG. 30 is a front view of the pointer housing;

FIG. 31 is a partially broken-away perspective view of a materialremoval gauge constructed in accordance with an alternate embodiment ofthe present invention;

FIG. 32 is an exploded perspective view of a portion of the portableplaner mechanism of FIG. 1, illustrating the dust collection system ingreater detail;

FIG. 33 is a sectional view taken along the line 33-33 of FIG. 1;

FIG. 34 is a sectional view taken along the line 34-34 of FIG. 1;

FIG. 35 is a side view of a portion of the power take-off mechanismillustrating the support plate as positioned in the neutral position;

FIG. 36 is a side view similar to that of FIG. 35 but illustrating thesupport plate rotated upwardly to employ the power input portion of thepower take-off mechanism to rotate the output portion of the powertake-off mechanism in a first rotational direction;

FIG. 37 is a side view similar to that of FIG. 35 but illustrating thesupport plate rotated downwardly to employ the power input portion ofthe power take-off mechanism to rotate the output portion of the powertake-off mechanism in a second rotational direction;

FIG. 38 is a perspective view illustrating a power take-off mechanismconstructed in accordance with an alternate embodiment of the presentinvention;

FIG. 39 is a side view of the power take-off mechanism of FIG. 38illustrating the support plate rotated upwardly to employ the powerinput portion of the power take-off mechanism to rotate the outputportion of the power take-off mechanism in a first rotational direction;and

FIG. 40 is a side view similar to that of FIG. 39 but illustrating thesupport plate rotated downwardly to employ the power input portion ofthe power take-off mechanism to rotate the output portion of the powertake-off mechanism in a second rotational direction.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to FIG. 1 of the drawings, a planer mechanism constructedin accordance with the teachings of the present invention is generallyindicated by reference numeral 10. With additional reference to FIG. 2,the planer mechanism 10 is shown to include a planer carriage assembly12, a base assembly 14, a planer carriage elevation mechanism 16, aplaner carriage locking mechanism 18, a carriage height settingmechanism 20, a height scale mechanism 22, a material removal gauge 24,a dust collection system 26 and a power take-off mechanism 28.

Planer Carriage Assembly

In FIG. 3, the planer carriage assembly 12 is illustrated to include acarriage 40, a motor assembly 42, a gearbox 44, a first roller assembly46, a second roller assembly 48 and a cutterhead assembly 50, which willbe discussed in more detail below. The carriage 40 is a unitarily formedstructure having a cutter pocket 54, two pair of square apertures 58 anda plurality of nut apertures 60, which will be discussed more detail,below. The cutter pocket 54 is shown to include a horizontally-extendingslot 62 that is formed through the top and bottom surfaces 64 and 66,respectively, of the carriage 40, and a pair of bearing apertures 68that extend through the opposite sides 70 of the carriage 40 andintersect the slot 62. The cutter pocket 54 is sized to support thecutterhead assembly 50 for rotation therein.

With additional reference to FIGS. 3 a and 3 b, the motor assembly 42 isillustrated to include a motor 80 and a switch assembly 82. The motor 80is fixedly but removably coupled to the carriage 40 forwardly of thecutter pocket 54 and includes a housing shell 84, a conventional stator86, a rotor 88, a housing end cap 90 and a pair of electric terminals 92that electrically couple the motor 80 to the switch assembly 82. Thehousing shell 84 is fixedly coupled to the carriage 40 via a pluralityof threaded fasteners 94 (FIG. 2). The housing shell 84 iscontainer-like in shape, having a first end 96, which is substantiallyclosed, a second end 98, which is open, and a plurality of air inletapertures 100 that are located proximate the first end 96. The stator 86is fixed to the housing shell 84 and defines an aperture 102 in whichthe rotor 88 rotates. The housing end cap 90 is removably coupled to thehousing shell 84 via a plurality of screws 104 and substantially coversthe second end 98. The housing end cap 90 includes a shaft aperture 106and a plurality of cooling vents 108, which will be discussed in greaterdetail, below.

The rotor 88 includes a shaft 110 having first and second end portions112 and 114, respectively. The first end portion 112 of the shaft 110 isrotatably supported by a first bearing 116 that is coupled to the firstend 96 of the housing shell 84. The first end portion 112 of the shaft110 extends outwardly past the housing shell 84 and is fixedly coupledto a drive pulley 118 which coupled to a belt 120 that is employed totransmit rotary power to the cutterhead assembly 50. The second endportion 114 of the shaft 110 is rotatably supported by a second bearing122 that is coupled to the housing end cap 90. The second end portion114 of the shaft 110 extends outwardly through the shaft aperture 106 inthe housing end cap 90 and includes a pair of parallel flats 124 and athreaded end portion 126. The second end portion 114 of the shaft 110will be discussed in more detail, below.

The switch assembly 82 includes a switch 130 that is conventionallyemployed to selectively couple the motor 80 to a source of electricpower. The switch assembly 82 is coupled to a forward facing portion ofthe housing shell 84 in a position where the switch is easily accessedby the operator of the planer mechanism 10.

Each of the first and second roller assemblies 46 and 48 is shown toinclude a pair of bushings 140, a pair of compression springs 142, apair of brackets 144, a roller 146, at least one sprocket 148 and aretaining ring 150. Each of the bushings 140 is illustrated to have acylindrical shaft aperture 152 and to be generally square in shape,conforming to the size of the square apertures 58 formed in the carriage40. Each bracket 144 is coupled to the bottom surface 66 of the carriage40 and limits the downward movement of the bushing 140 in the squareaperture 58. The ears 154 on the brackets 144 likewise limit the lateralmovement of the bushing 140 in the square aperture 58, thus ensuringthat the bushing 140 does not slide outwardly past the side 70 of thecarriage 40. Each compression spring 142 is disposed between the top ofthe bushing 140 and the top of the square aperture 58 and exerts abiasing force onto the bushing 140 which urges the bushing 140downwardly toward the bracket 144.

The roller 146 includes a cylindrical body portion 160 and first andsecond roller ends 162 and 164, respectively. Each of the first andsecond roller ends 162 and 164 is shown to have a cylindrical shaftportion 166 for engaging the shaft aperture 152 in an associated one ofthe bushings 140. Each of the first roller ends 162 and the secondroller end 164 of the roller 146 associated with the second rollerassembly 48 also includes a sprocket portion 168 to which one of thesprockets 148 is coupled. Various securing means may be employed forsecuring the sprocket 148 to the sprocket portion 168, includingthreaded connections to the roller 146 and press-fitting the sprocket148 to the roller 146. In the particular example provided, anon-circular geometric feature (not specifically shown) is formed ontothe sprocket portion 168 and a mating non-circular geometric feature(not specifically shown) is formed into the sprocket 148 to rotatablyfix the sprocket portion 168 and sprocket 148. In the embodiment shown,the non-circular geometric feature is oblong, having rounded ends and apair of parallel side walls. The sprocket 148 abuts the shoulder that isformed at the intersection of the non-circular geometric feature and theremaining portion of the roller 146. A conventional external retainingring 150 is employed to retain the sprocket 148 on the sprocket portion168.

A first drive chain 180 couples the sprockets 148 that are located onthe first roller end 162 of the rollers 146 of the first and secondroller assemblies 46 and 48 to one another, thereby ensuring that therotational speed of the rollers 146 is equal. A second drive chain 182couples the sprocket 148 that is located on the second roller end 164 ofthe roller 146 of the second roller assembly 48 to a sprocket 186 thatis coupled to the gearbox 44.

The gearbox 44 is coupled to a side of the carriage 40 and includes ageartrain 190 which receives a rotational input from the cutterheadassembly 50 via an output gear 192. The gearbox 44 is employed to reducethe speed of the rotational input and produce a rotational output thatis employed to drive the sprocket 186. The rotational speed of thesprocket 186 therefore dictates the rotational speed of the rollers 146.

With additional reference to FIGS. 4 through 4 b, the gearbox 44includes a gearbox housing 200, an input gear 202, a first reducing gear204, an intermediate shaft 206, a second reducing gear 208, a firstintermediate reducing gear 210, a second intermediate reducing gear 212,a final reduction gear 214, an output shaft 216, a key member 218, ashift fork 220 and a speed selector lever 224. The gearbox housing 200is formed from a pair of housing halves 230 which collectively define ageartrain cavity 232 having an input aperture 234, an output aperture236, a selector lever aperture 238 and a plurality of recessed shaftsupport bosses 240.

The output gear 192 that is coupled to the cutterhead assembly 50extends into the input aperture 234 in the gearbox housing 200 toprovide the geartrain 190 with a rotational input. The input gear 202 isfixed to a shaft portion 250 of the first reducing gear 204. A firstpair of the shaft support bosses 240 journally supports the firstreducing gear 204 for rotation within the geartrain cavity 232 about anaxis that is parallel to the rotational axis of the output gear 192. Theinput gear 202 includes a plurality of gear teeth 256 which aremeshingly engaged to the output gear 192.

A second pair of the shaft support bosses 240 journally supports theintermediate shaft 206 for rotation within the geartrain cavity 232about an axis that is parallel to the rotational axis of the output gear192. The second reducing gear 208, the first intermediate reducing gear210 and the second intermediate reducing gear 212 are fixed for rotationwith and spaced apart along the length of the intermediate shaft 206.The teeth 260 of the first reducing gear 204 are meshingly engaged withthe teeth 262 of the second reducing gear 208.

The final reduction gear 214 is illustrated to have a set of first gearteeth 264, a set of second gear teeth 268 having a pitch diameter thatis relatively smaller than the pitch diameter of the of the set of firstgear teeth 264, a collar portion 270 and a shaft aperture 272 that isconfigured to engage the output shaft 216 in a slip-fit manner. Thecollar portion 270 extends outwardly from the portion of the finalreduction gear 214 on which the set of second gear teeth 268 are formedand includes an annular recess 276 that extends around its circumferenceand which defines a pair of opposite sidewalls 278 and 280.

The output shaft 216 is journally supported by the output aperture 236and an associated shaft support boss 240 that is formed into the gearboxhousing 200. The key member 218 is coupled to the output shaft 216 andoperatively rotatably coupled the output shaft 216 and the finalreduction gear 214. The distal end of the output shaft 216 extends outof the gearbox housing 200 and is coupled to the sprocket 186.

The speed selector lever 224 is supported by the speed selector leveraperture 238 for linear movement along an axis coincident with thelongitudinal axis of the speed selector lever 224. The shift fork 220includes U-shaped fork portion 286 and a coupling portion 288. The forkportion 286 includes a U-shaped aperture 290 and a pair of furcations292 that are configured to fit into the annular recess 276. The couplingportion 288 is fixedly coupled to an end of the speed selector lever224. The speed selector lever 224 is employed to slide the finalreduction gear 214 on the output shaft 216 to selectively engage thefinal reduction gear 214 with one of the first and second intermediatereducing gears 210 and 212. More specifically, the speed selector lever224 is employed to push or pull the shift fork 220 along an axis that isparallel to the rotational axis of the output shaft 216 so that thefurcations 292 of the shift fork 220 bear against the sidewalls 278 or280 to move the final reduction gear 214 along the output shaft 216 topermit the set of first gear teeth 264 to be engaged with the teeth 294of the first intermediate reducing gear 210 or to permit the set ofsecond gear teeth 268 to be engaged with the teeth 296 of the secondintermediate reducing gear 212. As the pitch diameter of the firstintermediate reducing gear 210 is smaller than the pitch diameter of thesecond intermediate reducing gear 212, engagement of the final reductiongear 214 to the first intermediate reducing gear 210 will result in arotational speed of the sprocket 186 that is relative slower as comparedto the rotational speed of the sprocket 186 when the final reductiongear 214 is engaged to the second intermediate reducing gear 212.

During the operation of the planer mechanism 10, the compression springs142 urge the bushings 140 downward to force the rollers 146 into contactwith the workpiece 300 (FIG. 1). The rotational speed of the rollers 146is equal and controlled by the gearbox 44 such that the workpiece 300 isdrawn through the planer mechanism 10 at a controlled rate. Accordingly,the speed selector lever 224 may be employed to selectively rotate therollers 146 at one of two predetermined rotational speeds.

Composite Planer Base Assembly

In FIG. 5, the base assembly 14 is illustrated to include a basestructure 310, a plate structure 312 and a plurality of fasteners 314for fixedly coupling the base and plate structures 310 and 312 to oneanother. The base structure 310 is preferably unitarily formed from alightweight material, such as aluminum or reinforced plastic, andincludes a base body portion 320 and a plurality of base flanges 322.Examples of suitable forming processes for forming the base structure310 include casting (including die casting) and molding processes.

The base body portion 320 includes a plurality of interlinked structuralwebs 324 that define a support surface or upper surface 326. The uppersurface 326 is discontinuous, having a plurality of generally open voidspaces 328. Mounting apertures 330, which are employed for locating andsecuring the plate structure 312 to the base structure 310, are formedinto the webs 324 at predetermined locations. With additional referenceto FIG. 6, each of the mounting apertures 330 is shown to include acylindrically-shaped body 332, a first counterbored portion 334, whichextends downwardly from the body 332 and intersects the bottom surface336 of the base structure 310, and a second counterbored portion 338,which extends upwardly from the body 332 and intersects the uppersurface 326 of the base structure 310.

Each of the base flanges 322 includes a pair of guide post mountingapertures 340 that are undersized from their finished dimension by apredetermined amount. The guide post mounting apertures 340 arepreferably positioned such that the forwardly positioned guide postmounting apertures 340 f are somewhat inboard of the rearwardlypositioned guide post mounting apertures 340 r for purposes that will bediscussed in greater detail, below.

The one-piece plate structure 312 is preferably formed from cast ironand includes a plate member 344 and a plurality of fastening bosses 346.The plate member 344 is generally rectangular in shape, having upper andlower surfaces 348 and 350, respectively, that are cast to be flat andparallel within standard casting tolerances. The fastening bosses 346are cylindrically shaped and extend outwardly away from the lowersurface 350 of the plate member 344. A threaded aperture 352 is formedinto the distal end of each fastening boss 346 and is configured tothreadably engage a threaded portion 354 of an associated one of thefasteners 314. The outer diameter of each fastening boss 346 isconfigured to fit within the second counterbored portion 338 of themounting aperture 330.

Prior to the assembly of the base structure 310 and the plate structure312, one or both of the upper and lower surfaces 326 and 336 of the basestructure 310 may optionally be machined so as to render these surfacesflatter and more parallel to one another as compared to their “as cast”condition. However, it is presently preferred that the base structure310 not be machined prior to the assembly of the base and platestructures 310 and 312. The base and plate structures 310 and 312 arealigned relative to one another such that each of the fastening bosses346 is disposed in the second counterbored portion 338 of an associatedmounting aperture 330. The fasteners 314, which are illustrated to besocket-head cap screws 360, are introduced to the opposite end of themounting apertures 330 and threadably engaged to the threaded aperture352 formed in the associated fastening boss 346. As the fastening bosses346 do not contact the end 362 of the second counterbored portion 338,the clamping force that is generated by the fasteners 314 operativelymaintains the lower surface 350 of the plate member 344 in abutment withthe upper surface 326 of the base structure 310, permitting the platestructure 312 to cover the void spaces 328 in the base structure 310.

Once assembled, the base assembly 14 is machined to provide a referencesurface or planing surface 370 that is flat and perpendicular to theaxes 372 of the guide post mounting apertures 340, as well as toposition the axes 372 of the guide post mounting apertures 340 in apredetermined location relative to one another. For example, the baseassembly 14 may be fixtured in a grinding machine, such as a Blanchardgrinder (not shown), to permit the planing surface 370 of the platestructure 312 to be machined flat. Thereafter, the base assembly 14 maybe fixtured into a boring machine having a multi-spindle boring head(not shown) using the planing surface 370 of the plate structure 312 asa datum to permit the guide post mounting apertures 340 to be bored totheir proper size and with their axes located in a desired mannerrelative to one another and perpendicular to the planing surface 370. Asanother example, the base assembly 14 may be fixtured in an automatedmachining device such that the bottom surface 336 of the base structure310 is clamped against a fixture to permit the planing surface 370 ofthe plate structure 312 and the guide post mounting apertures 340 to bemachined without unclamping the base assembly 14 from its fixture orotherwise changing the orientation of the base assembly 14 relative tothe fixture. Suitable automated machining devices include CNC machiningcenters having a tool changer with a plurality of selectable tool bits,dial indexing machines having a plurality of machining stations, andtransfer machines having a plurality of machining stations.

Configuration of the base assembly 14 in this manner is highlyadvantageous in that the base assembly 14 is accurately constructed, yetextremely lightweight relative to conventionally configured planerbases, robust in design, and relatively inexpensive. Those skilled inthe art will appreciate, however, that the base assembly of the presentinvention may be constructed somewhat differently while still permittingthe attainment of these benefits. For example, the fastening bosses 346may be omitted from the plate structure 312′, as illustrated in FIG. 7.In this example, mounting apertures 330′ having a countersunk portion380 are formed through the plate structure 312′ and threaded apertures382 are formed into the webs 324′ of the base structure 310′. Flat headcap screws 384, having a conical head 386, which is configured to matewith the countersunk portion 380 of the mounting apertures 330, and athreaded portion 388, which is sized to threadably engage the threadedapertures 382, are employed to both locate the plate structure 312′relative to the base structure 310′ and couple the base and platestructures 310′ and 312′ to one another. As with base structure 310, theupper and lower surfaces 326′ and 336′ of the base structure 310′ andthe upper and lower surfaces 348′ and 350′ of the plate structure 312′are preferably not machined prior to their assembly so as to minimizethe cost of the base assembly 14′.

Planer Carriage Elevation Mechanism

In FIGS. 2 and 8, the planer carriage elevation mechanism 16 is shown toinclude a plurality of threaded guide posts 400, a plurality of nutassemblies 402 and an adjustment mechanism 404. In the embodimentillustrated, the threaded guide posts 400 include a cylindrically-shapedpin portion 410 and a threaded adjustment portion 412. The pin portion410 is precisely sized to engage an associated one of the guide postmounting apertures 340 with an interference fit, such as in ashrink-fit, or more preferably, a press-fit manner. Construction in thismanner is advantageous in that the interference fit between the guidepost 400 and the base structure 310 reliably locates the axis 414 of theguide post 400 in an orientation that is coincident the axis 372 of theguide post mounting aperture 340, as well as ensures that they willremain fixedly interconnected during the normal operation of the planermechanism 10. After the pin portion 410 has been inserted into anassociated guide post mounting aperture 340, conventional set screws 416and/or pins, such as roll pins or dowel pins, may be employed to furtherassure that the guide posts 400 will not rotate relative to the basestructure 310 during the operation of the planer mechanism 10. Althoughthe guide posts 400 are illustrated as being press-fit to the basestructure 310, those skilled in the art will understand, however, thatany appropriate coupling means may be employed to fix the guide posts400 to the base structure 310. Such coupling means are generally wellknown in the art and therefore, need not be discussed in detail.

The adjustment portion 412 of the guide post 400 preferably includes asingle helical threadform 420 having an axis that is coincident with theaxis 414 of the guide post 400. Examples of suitable threadforms includeAcme screw threads, centralizing Acme screw threads, square threads,modified square threads, and conventional screw threads such as UnifiedNational screw threads and metric M and MJ profile threads. It ispresently preferred that the threadform 420 be formed in a materialremoving machining process, such as turning or grinding, so as to ensurethat the axis of the threadform 420 is coincident with the axis 414 ofthe guide post 400. Alternatively, the threadform 420 may be formed in amachining process that does not remove material, such as roll forming,provided that the axis of the threadform 420 is properly oriented. Alsopreferably, the guide posts 400 are heat treated to increase thestrength and durability of the adjustment portion 412.

Each nut assembly 402 includes an upper lock nut 430, a lower lock nut432, an annular holder 434, first and second retaining rings 436 and438, respectively, and a bushing 440. The upper lock nut 430 is shown toinclude a flange portion 450, a body portion 452 and an aperture 454formed through the flange and body portions 450 and 452. The flangeportion 450 is cylindrically shaped and extends radially outwardly fromthe body portion 452. A plurality of semi-circular spring foot apertures456 are spaced apart at regular intervals around the outer circumferenceof the flange portion 450. The spring foot apertures 456 are discussedin more detail, below. The body portion 452 is also cylindricallyshaped, being sized to fit within a nut aperture 60 formed in thecarriage 40. The body portion 452 extends downwardly from the flangeportion 450 and terminates at a coupling tab 458. In the exampleprovided, the coupling tab 458 is formed with a pair of parallel endwalls 460, each of which being oriented such that they lie in a planespaced apart from and parallel to the longitudinal axis of the upperlock nut 430. The aperture 454 includes a threaded portion 462 that isconfigured to threadably engaged the threadform 420 of the guide post400.

The lower lock nut 432 includes cylindrically shaped upper and lowerbody portions 470 and 472, respectfully, a mid-flange 474 that ispositioned between the upper and lower body portions 470 and 472 and anaperture 476 that extends completely through the lower lock nut 432. Theupper body portion 470 has an outer diameter that is substantially equalto that of the body portion 452 of the upper lock nut 430 and includes aslotted aperture 478 that is sized to receive the coupling tab 458 thatis formed onto the upper lock nut 430. Preferably, little clearanceexists between the coupling tab 458 and the slotted aperture 478 so asto minimize the amount by which the upper and lower lock nuts 430 and432 are permitted to rotate relative to one another when the couplingtab 458 is engaged in the slotted aperture 478. The mid-flange 474extends radially outwardly of the upper and lower body portions 470 and472 and includes upper and lower flange surfaces 480 and 482,respectively, and a plurality of conventionally formed worm gear teeth484, which are formed into the outer circumference of the mid-flange474. The lower body portion 472 extends downwardly from the mid-flange474 and has an outer diameter that is sized to engage the inner diameterof the bushing 440. The aperture 476 includes a threaded portion 486that is configured to threadably engaged the threadform 420 of the guidepost 400.

The lower lock nut 432 and the body portion 452 of the upper lock nut430 are illustrated to be disposed in the nut aperture 60 in thecarriage 40 such that the coupling tab 458 is engaged to the slottedaperture 478. With additional reference to FIG. 9, the fit between thecoupling tab 458 and the slotted aperture 478 is almost line-to-line,thereby substantially limiting the amount by which the upper and lowerlock nuts 430 and 432 are able to rotate relative to one another afterthe coupling tab 458 and the slotted aperture 478 have been engaged toeach other. A retaining ring groove 488, which is formed into the lowerbody portion 472, receives the first retaining ring 436 to retain thebushing 440 to the lower body portion 472. The outer diameter of thebushing 440 is configured to engage the inner diameter of the annularholder 434 in a press fit manner. The outer diameter of the annularholder 434 is sized to engage the nut aperture 60 in the carriage 40 ina press-fit manner. The second retaining ring 438 is a conventionalinternal retaining ring that is configured to engage a retaining ringgroove 490 formed into the nut aperture 60 in the carriage 40 to therebyprevent the annular holder 434 from moving downwardly in the nutaperture 60 beyond a predetermined distance.

In FIGS. 2 and 8, the adjustment mechanism 404 is shown to include afront axle 500, a rear axle 502, a plurality of geared worms 504, a pairof pulleys 506, a belt 508 and a hand wheel 510. Bushings 512 orbearings are preferably employed to support the front and rear axles 500and 502 for rotation within front and rear axle apertures 514 and 516,respectively, formed in the carriage 40. The hand wheel 510 and one ofthe pulleys 506 are coupled to the opposite ends of the front axle 500.Two of the geared worms 504 are coupled for rotation with the front axle500 and are positioned along the length of the front axle 500 so as tomeshingly engage the worm gear teeth 484 that are formed into thecircumference of the mid-flange 474 of the forward pair of lower locknuts 432. Similarly, a pair of the geared worms 504 are coupled forrotation with the rear axle 502 and positioned along the length of therear axle 502 so as to meshingly engage the worm gear teeth 484 that areformed into the circumference of the mid-flange 474 of the rearward pairof lower lock nuts 432. The remaining pulley 506 is also coupled forrotation with the rear axle 502 and is positioned such that it islocated in a plane that is both perpendicular to the front and rearaxles 500 and 502 and in which the other pulley 506 is located. In theparticular example provided, the belt 508 has a conventional V-shapedcross-section and is engaged to the pulleys 506 in a conventionalmanner.

A rotational input to the hand wheel 510 operates to rotate the frontaxle 500. The pulley 506 that is coupled to the front axle 500 the belt508 and the pulley 506 that is coupled to the rear axle 502 cooperate totransmit the rotational input to the rear axle 502, causing the rearaxle 502 to rotate in a manner that is identical to that of the frontaxle 500. As the geared worms 504 are coupled for rotation with thefront and rear axles 500 and 502 and meshingly engaged to the worm gearteeth 484 that are formed into the circumference of the mid-flange 474of the lower lock nuts 432, the rotational input is also transmittedthrough the geared worms 504 and into the worm gear teeth 484 of theirassociated lower lock nut 432, causing the lower lock nuts 432 torotate. As the coupling tab 458 of the upper lock nut 430 is engaged inthe slotted aperture 478 of the lower lock nut 432, rotation of thelower lock nuts 432 causes the upper lock nuts 430 to rotate in anidentical manner. The common rotation of the upper and lower lock nuts430 and 432 causes the nut assemblies 402 to traverse along theadjustment portion 412 of the guide posts 400 to thereby lift or lowerthe carriage 40 in a highly controlled and accurate manner.

Those skilled in the art will appreciate, however, that the planercarriage elevation mechanism 16 may be constructed somewhat differentlywhile still permitting the carriage to be positioned in a highlycontrolled and accurate manner. For example, the planer carriageelevation mechanism 16 may be constructed as shown in FIG. 10. In thisembodiment, sprockets 520 are formed onto the mid-flange 474 a of eachof the lower lock nuts 432 a. A drive chain 522 which is formed as aloop that encircles the guide posts 400, engages the sprockets 520 aswell as an input sprocket 524 that is coupled for rotation with the handwheel 510. Rotation of the hand wheel 510 rotates the input sprocket524, causing the drive chain 522 to rotate around the guide posts 400and rotate the lower lock nuts 432.

Those skilled in the art will also understand that various mechanicalequivalents can be readily substituted for several of the componentsthat are shown in the above embodiments. For example, sprockets and adrive chain can be readily substituted for the pulleys 506 and belt 508that are illustrated in FIG. 8. As another example, pulleys and a beltcan be substituted for the sprockets 520 and drive chain 522 that areillustrated in FIG. 10.

Planer Carriage Locking Mechanism

With renewed reference to FIGS. 2, 8, 9 and 11, the planer carriagelocking mechanism 18 is illustrated to include a plurality of camassemblies 600, a plurality of link arms 602 and an input lever 604.Each of the cam assemblies 600 is shown to include an upper cam 610, alower cam 612 and a biasing spring 614. The upper cam 610 is an annularring having a central aperture 620, which is sized to receive the bodyportion 452 of the upper lock nut 430 in a slip-fit manner, and aplurality of mounting lugs 622 that are formed onto its outercircumference. The top surface 624 of the upper cam 610 is illustratedto be flat and configured to contact the bottom surface 626 of theflange portion 450 of an associated upper lock nut 430. With additionalreference to FIG. 12, the lower surface 628 of the upper cam 610 isshown to include a plurality of tapered ramp members 630, each of whichhaving a relatively thin nose portion 632 and tapering outwardly anddownwardly to and ending abruptly at a relatively thick end portion 634.The ramp members 630 extend around the circumference of the upper cam610, being linked to one another such that the nose portion 632 of eachramp member 630 abuts the end portion 634 of an adjacent ramp member630.

The lower cam 612 is also an annular ring, having a central aperture640, which is sized to receive the upper body portion 470 of the lowerlock nut 432 in a slip fit manner, a substantially flat lower surface644, which is configured to abut the top surface 64 of the carriage 40,and an upper surface 646 having a plurality of ramp members 650 that areconfigured to mate with the ramp members 630 formed onto the lowersurface 626 of the upper cam 610. The lower cam 612 is preferablyfixedly coupled to the carriage 40 with, for example, low-profilefasteners such as flat head cap screws (not shown).

The cam assembly 600 at the location indicated by reference letter A isgenerally similar to the cam assemblies 600 discussed above, but alsoincludes a mounting flange 654 for coupling the upper cam 610 to aninput lever 604. The input lever 604 extends forwardly past the carriage40, providing the operator of the planer mechanism 10 with a comfortableand easily manipulated means for controlling the planer carriage lockingmechanism 18.

The biasing spring 614 operates to bias the rotational position of theupper cam 610 relative to the lower cam 612 from a neutral position,illustrated in FIG. 12, wherein the ramp members 630 of the upper cam610 completely confront the ramp members 650 of the lower cam 612, to alocked position, illustrated in FIG. 13. The biasing spring 614 isillustrated to be a conventional tension spring 658 at the locationdesignated by reference letter A and a conventional torsion spring 660at the locations designated by reference letters B, C and D. The tensionspring 658 is coupled to one of the mounting lugs 622 at a first end andto the carriage 40 at a second end. Each torsion spring 660 is disposedover an associated upper cam 610 and around the flange portion 450 of anassociated upper lock nut 430. The torsion spring 660 includes a firstfoot 662, which extends downwardly and engages one of the mounting lugs622, and a second foot 664, which extends upwardly and engages one ofthe spring foot apertures 456 that is formed in the flange portion 450of the upper lock nut 430.

The link arms 602 are coupled to the mounting lugs 622 in the upper cams610 via shoulder screws 670. The link arms 602 are configured such thata rotational input to the upper cam 610 at location A via the inputlever 604 is transmitted through the link arms 602 causing each of theother upper cams 610 to rotate in an equal amount and in the samedirection.

When it is necessary to adjust the vertical position of the carriage 40,the input lever 604 is positioned such that each of the upper cams 610are positioned in their neutral position. In this condition, the planercarriage locking mechanism 18 does not interfere with the planercarriage elevation mechanism 16 and as such, the carriage 40 can beraised or lowered as desired. Once the carriage 40 has been located to adesired position, the input lever 604 is released, permitting thebiasing springs 614 to provide a rotational input to each of the uppercams 610. This rotational input causes the upper cams 610 to rotaterelative to their associated lower cam 612 into a locked position, whichagain is illustrated in FIG. 13. In this condition, the lower and uppersurfaces 626 and 646 of the upper and lower cams 610 and 612,respectively, are still in contact with one another. However, as theupper and lower cams 610 and 612 have rotated relative to one another,the end portions 634 of the ramp members 630 on the upper cam 610 haveslid closer toward the end portions 634 of the ramp members 650 on thelower cams 612, thereby increasing the overall distance between theupper surface 624 of the upper cam 610 and the lower surface 644 of thelower cam 612, the distance being designated by reference letter “d”.

Accordingly, the positioning of the upper cam 610 into the lockedposition generates an axial force that tends to push the upper cam 610(and upper lock nut 430) away from the carriage 40. Therefore, as eachof the lower lock nuts 432 are rotatable within their associated nutaperture 60 but restrained vertically within the nut aperture 60 by thefirst and second retaining rings 436 and 438, the axial force istransmitted through the carriage 40 to the lower lock nut 432. As thoseskilled in the art will readily appreciate, the opposite verticalmovement of the upper and lower lock nuts 430 and 432 forces thethreaded portion 462 of the upper lock nut 430 into contact with a firstside 672 of the threadform 420 and the threaded portion 486 of the lowerlock nut 432 into contact with an opposite side 674 of the threadform420 to inhibit relative rotation between each of the nut assemblies 402and their associated guide post 400 to thereby lock the verticalposition of the nut assemblies 402 relative to their guide post 400.

While the cam assemblies 600 have been illustrated with upper and lowercams 610 and 612 with a multiplicity of ramp members 630 and 650,respectively, those skilled in the art will understand that anyappropriate number of ramp members 630 and 650 may be used. In thisregard, the number of ramp members 630 may not be equal to the number oframp members 650. In a presently preferred embodiment, the quantity ofthe ramp members 630 is equal to three and the number of ramp members650 is equal to the number of ramp members 630.

Cutter Head Assembly With Quick Change Cutting Blade

With reference to FIGS. 3 and 14, the cutterhead assembly 50 is shown tobe supported for rotation in the cutter pocket 54 formed in the carriage40 by a pair of bearings 700. In the particular example illustrate, thecutterhead assembly 50 includes a cutter head 702, a plurality of cutterblades 704, a plurality of blade binders 706 and a pulley 708. Thecutter head 702 is illustrated to have a body 710 and first and secondshaft ends 712 and 714 that are coupled to the opposite ends of the body710. The body 710 has a cross-section that generally conforms to that ofan equilateral triangle. Each side 716 of the body 710 is flat andincludes a plurality of threaded attachment apertures 718 and a pair oflocator apertures 720. In the example provided, the locator apertures720 are cylindrical holes, which are aligned along an axis 722 that isparallel the longitudinal axis 724 of the cutter head 702 and sized toengage a pair of locator pins 726 in a press-fit manner.

The first shaft end 712 includes a relatively short shoulder 730 thatextends out from the body 710 a sufficient distance to permit it to bepress-fit to the inner bearing race of an associated one of the bearings700. The second shaft end 714 includes a similar shoulder 732 formounting the other bearing 700, as well as a neck portion 734 havingcylindrical body 736 and a threaded end 738. The cylindrical body 736 issized to engage a shaft aperture 740 that is formed in the pulley 708. Akey member 742 engages slots 744 and 746 formed in the cylindrical body736 and the pulley 708, respectively, to inhibit relative rotationbetween the cutter head 702 and the pulley 708. A nut 748 is threadablyengaged to the threaded end 738 and exerts a clamping force that fixesthe pulley 708 onto the cylindrical body 736 and in abutment with theshoulder 732.

In the example illustrated, each of the cutter blades 704 is formed froma flat piece of an appropriate cutting blade material, such as highspeed steel. Each cutter blade 704 includes a tip portion 750 and amounting portion 752. The tip portion 750 is fixedly coupled to themounting portion 752 and includes a knife edge 754 which cuts theworkpiece during the planing operating. Alternatively, the tip portion750 of the cutter blades 704 may be formed either partly or in total byanother material, such as carbide, in a manner that is well known in theart, to provide the cutter blades 704 with a desired characteristic,such as wear resistance or lower overall cost. Also alternatively, asecond tip portion 750′ may be fixedly coupled to the opposite side ofthe mounting portion 752, thereby permitting the cutter blade 704 to beflipped relative to the cutter head 702 when the tip portion 750 isdulled or damaged.

The mounting portion 752 includes a plurality of clearance holes 760, afirst locating aperture 762 and a second locating aperture 764. Theclearance holes 760 are preferably through-holes having a diameter thatis somewhat larger than the major diameter of the threaded attachmentapertures 718 that are formed in the cutter head 702. The first locatingaperture 762 is illustrated to be a circular hole which is sized aboutequal to or just larger than the diameter of the associated locator pin726 in the cutter head 702 to provide a fit that is almost line-to-linearound the circumference of the locator pin 726. The second locatingaperture 764 is illustrated to be an oval slot, having a pair ofparallel sidewalls 768 that are spaced apart by a dimension that isabout equal to or just larger than the diameter of the associatedlocator pin 726 in the cutter head 702. The locator pins 726 cooperatewith the first and second locating apertures 762 and 764 to locate theknife edge 754 in a location that is parallel to the longitudinal axis724 of the cutter head 702 and spaced apart therefrom by a predetermineddistance.

The blade binders 706 are illustrated to have a first clamping section770 and a second clamping section 772. The first clamping section 770 isgenerally flat, being configured to abut the mounting portion 752 of thecutter blade 704 when it is attached to the cutter head 702. The firstclamping section 770 includes a plurality of clearance holes 774, whichhave a diameter that is somewhat larger than the major diameter of thethreaded attachment apertures 718 that are formed in the cutter head702, and a pair of locator clearance holes 776, which are sized toreceive the locating pins 726. The locator clearance holes 776 mayextend completely through the first clamping section 770 as shown, ormay be formed only partly through the first clamping section 770, beingof a sufficient depth so as to prevent the abutting face 778 of thefirst clamping section 770 from contacting the locating pins 726. Thesecond clamping section 772 is fixedly coupled to the first clampingsection 770 and is configured to wrap around the trailing edge 780 ofthe cutter blade 704 and into contact with the side 716 of the cutterhead 702.

Conventional threaded fasteners, such as button head cap screws 782 areplaced through the clearance holes 774 and 760 in the blade binder 706and the cutter blade 704, respectively, and threadably engaged to thethreaded attachment apertures 718 in the cutter head 702 to produce aclamping force that fixedly but removably couples the blade binder 706and cutter blade 704 to the cutter head 702. Those skilled in the artwill readily appreciate that the locating pins 726 and first and secondlocating apertures 762 and 764 cooperate to permit the knife edge 754 ofthe tip portion 750 of the cutter blade 704 to be accurately andrepeatably positioned relative to the longitudinal axis 724 of thecutter head 702, thereby rendering the replacement of the cutter blades704 a relatively uncomplicated and quick task. Those skilled in the artwill also understand that the design of the cutterhead assembly 50 maybe simplified somewhat, for example, by replacing the locating pins 726and a corresponding number of screws 782, with conventional andcommercially available shoulder screws. Modifications that wouldfacilitate the shoulder screws, such as the counterboring of the cutterhead 702 to accept the shoulder of the shoulder screws, are well withinthe capabilities of one skilled in the art and as such, will not bediscussed in detail herein.

Cutter Head Assembly With Tool-less Blade Mounting System

With reference to FIG. 15 through 18, an alternative cutterhead assembly50 a, which is somewhat similar to the cutterhead assembly 50 isillustrated in detail to include a cutter head 702 a, a plurality ofcutter blades 704 a, a cutter blade keeper mechanism 800 and a cutterblade releasing mechanism 802. In contrast to the cutter head 702, thecutter head 702 a has body 710 a that is generally cylindrically shapedand which includes a plurality of longitudinally extending bladeapertures 810. Each blade aperture 810 is shown to include a generallyflat reaction wall 812, a locating member 814 fixedly coupled to thereaction wall 812 and a forward wall 816 that tapers rearwardly towardthe reaction wall 812 and outwardly toward the outer circumference ofthe body 710 a. The locating member 814 is illustrated to be asemi-cylindrical ridge 820 that is formed into the body 710 a, beingparallel to and spaced apart from the longitudinal axis 724 a of thecutter head 702 a by a predetermined distance.

The cutter blades 704 a are illustrated to include a tip portion 750 anda mounting portion 752 a. The tip portion 750 is identical to the tipportion 750 of the cutter blades 704 and as such, need not be describedin detail. The mounting portion 752 a is generally flat, having firstand second abutting surfaces 824 and 826, respectively. A recess 830that is configured to engage the locating member 814 is formed into thefirst abutting surface 824 and permits the first abutting surface 824 tobe abutted directly against the reaction wall 812.

The cutter blade keeper mechanism 800 includes a keeper element 834 anda spring member 836. The keeper element 834 includes first and secondinwardly tapering sidewalls 838 and 840, respectively. The spring member836 biases the keeper element 834 in a direction out of the bladeaperture 810, driving the sidewalls 838 and 840 into abutment with thesecond abutting surface 826 of the cutter blade 704 a and the forwardwall 816 of the blade aperture 810, respectively, to thereby fix thecutter blade 704 a relative to the cutter head 702 a. The force exertedonto the cutter blade 704 a that is attributed to the spring member 836is relatively small and normally would not be sufficient to ensure thatthe cutter blade 704 a is properly retained in the blade aperture 810when the cutter blade 704 a was subjected to a relatively high cuttingforce. However, during the operation of the planer mechanism 10, acentrifugal force is generated in response to the rotation of the cutterhead 702 a. The centrifugal force that is exerted onto the keeperelement 834 tends to force the keeper element 834 in a directionoutwardly from the cutter head 702 a, thereby wedging the keeper element834 between the second abutting surface 826 and the forward wall 816 andensuring that the cutter blade 704 a is properly retained in the bladeaperture 810, even when the cutter blade 704 a is subjected torelatively high cutting forces. As those skilled in the art will readilyappreciate, the sizing and tolerances of the blade aperture 810, thecutter blade 704 a and the keeper element 834 are preferably determinedin a manner that does not permit the outer surface 844 of the keeperelement 834 to extend radially outwardly beyond a predetermined designpoint, such as the outer circumference of the cutter head 702 a.

In FIGS. 17 and 18, the cutter blade releasing mechanism 802 is shown toinclude a pair of release levers 850 and a pair of lever locks 852. Therelease levers 850 are generally L-shaped having a keeper engagingportion 854 that is disposed generally perpendicularly to a handleportion 856. The release levers 850 are pivotally coupled to thecarriage 40 at the intersection between the keeper engaging portion 854and the handle portion 856, permitting the keeper engaging portion 854to be pivoted between a retracted position, shown in solid line in FIG.17, and an engaged position, shown in phantom in FIG. 17, wherein thekeeper engaging portion 854 is rotated downwardly into the cutter pocket54 in the carriage 40 and against the outer surface 844 of the keeperelement 834 to push the keeper element 834 downwardly and away from thecutter blade 704 a as illustrated in FIG. 18. In the embodimentillustrated, the tip 862 of the keeper engaging portion 854 is definedby a radius which permits the tip 862 to matingly engage the outersurface 844 of the keeper element 834. Those skilled in the art willunderstand, however, that the configurations of the tip 862 and theouter surface 844 are merely exemplary and as such, are not intended tolimit the scope of the present invention in any manner.

The lever locks 852 are fixedly coupled to the dust hood 870 that coversthe cutter pocket 54, extending downwardly from the dust hood 870 andagainst the handle portion 856 of the release levers 850. The leverlocks 852 are configured to inhibit the rotation of the release levers850 relative to the carriage 40 when the dust hood 870 is coupled to thecarriage 40 to thereby prevent the lever locks 852 from rotating out ofthe retracted position and into contact with the cutter head 702 a andcutter blades 704 a. Accordingly, when maintenance or removal of thecutter blades 704 a is required, the dust hood 870 is removed to bothpermit access to the cutterhead assembly 50 a as well as to permit therelease levers 850 to be positioned into the engaged position.

Carriage Height Setting Mechanism

With reference to FIGS. 2 and 19 through 21, the carriage height settingmechanism 20 is shown to include a stop adjustment assembly 900 and astop member 902. In the particular embodiment illustrated, the stopadjustment assembly 900 includes a shaft member 904 and a rotaryselector knob 906. The shaft member 904, which is illustrated to be aconventional shoulder bolt 908, includes a threaded portion 910, whichis fixedly coupled to a side of the carriage 40, a shoulder portion 912,which rotatably supports the rotary selector knob 906, and a headportion 914, which ensures that the rotary selector knob 906 is retainedon the shoulder portion 912.

The rotary selector knob 906 includes a gripping portion 920, aplurality of cam sectors 922 and a mounting aperture 924 through whichthe shoulder portion 912 of the shoulder bolt 908 is disposed. Thegripping portion 920 includes a plurality of cylindrical grooves 926which are configured to receive the fingers and thumbs of the operatorof the planer mechanism 10 so that the rotary selector knob 906 may beeasily rotated about the shoulder bolt 908. The gripping portion 920also includes a scale 928 having a plurality of height markings 930,which when employed in conjunction with a reference datum 932 fixedlycoupled to the carriage 40, permits the operator to readily identify therotational position of the rotary selector knob 906 and morespecifically, the particular cam sector 922 that has been selected foruse in conjunction with the stop member 902.

The cam sectors 922 are fixedly coupled to the inward side 934 of thegripping portion 920. In the particular embodiment illustrated, therotary selector knob 906 is configured with six (6) equally sized camsectors 922, with each of the cam sectors 922 being defined by anincluded angle of approximately 60°. Each cam sector 922 has a camsurface 936 that is disposed radially outwardly from the axis 938 of themounting aperture 924 by a predetermined distance. As shown, a first oneof the cam surfaces 936 a is spaced a first distance away from the axis938 and each subsequent cam surface 936 b, 936 c, 936 d, 936 e and 936 fis located a predetermined distance further away from the axis 938 thanthe cam surface 936 of the immediately preceding cam sector 922.

Those skilled in the art will understand that the number of cam sectors922 may be increased or decreased from that which is illustrated toprovide a desired number of cam surfaces. Those skilled in the art willalso understand that although the cam sectors 922 are defined by anequally sized included angle and the cam surfaces 936 are spacedradially outward from a minimum (cam surface 936 a) to a maximum (camsurface 936 f) in equal increments, the sizing of the cam sectors 922and the spacing apart of the cam surfaces 936 need not be equal.

Preferably, the stop adjustment assembly 900 also includes a means forinhibiting the rotation of the rotary selector knob 906 relative to thecarriage 40. Rotation inhibiting means, which are known in the art andneed not be discussed in detail herein, include, for example, a detentmechanism 940 and friction washers (not shown), which exert a force ontoa face of the rotary selector knob 906 that prevents the rotary selectorknob 906 from spinning freely on the shaft member 904.

In the example illustrated, the stop member 902 is illustrated toinclude a threaded stud 944 and a lock nut 946. The threaded stud 944 isthreadably engaged to a stud mounting aperture 948 formed into the basestructure 310. The distal end of the threaded stud 944 terminates at acontact tip 950 that is configured to contact the cam surfaces 936 ofthe cam sectors 922. Preferably, the contact tip 950 is defined by aspherical radius that ensures contact with the cam surfaces 936 in areliable and repeatable manner. The lock nut 946 is threadably engagedto the threaded stud 944 and rotated into contact with the basestructure 310 to generate a clamping force that fixes the threaded stud944 relative to the base structure 310.

In operation, the planer carriage assembly 12 is initially indexed to ahigher position than is ultimately desired. The operator next rotatesthe gripping portion 920 of the rotary selector knob 906 to align adesired height marking 930 on the scale 928 with the reference datum 932formed onto the carriage 40. The operator then rotates the hand wheel510 to lower the planer carriage assembly 12 in the manner discussedabove. As the planer carriage assembly 12 is being lowered, the camsurface 936 of the cam sector 922 which corresponds to the desiredheight marking 930 is simultaneously lowered onto the stop member 902.Contact between the contact tip 950 and the cam surface 936 inhibitsfurther lowering of the planer carriage assembly 12 as well asaccurately and repeatably positions the planer carriage assembly 12 suchthat the knife edge 754 of the cutter blades 704 are positioned abovethe planing surface 370 by a distance that is related to the heightmarking 930. Thereafter, the planer carriage locking mechanism 18 isemployed to lock the planer carriage assembly 12 in place.

As those skilled in the art will readily understand, the height of thecontact tip 950 relative to the base structure 310 must be calibratedprior to the use of the carriage height setting mechanism 20. Thecalibration process ensures that the amount by which the knife edge 754of the cutter blades 704 are positioned above the planing surface 370 isequal to the particular height marking 930 to which the rotary selectorknob 906 is adjusted. In its most basic form, the height of the contacttip 950 can be calibrated through an iterative process wherein thecarriage height setting mechanism 20 is employed to set the height ofthe planer carriage assembly 12, a workpiece is planed, the thickness ofthe workpiece is compared with the selected height marking 930 and thedifference between the height marking 930 and the thickness of theworkpiece is employed as necessary to adjust the location of the contacttip 950. The calibration process is complete when the stop member 902 isfully secured to the base structure 310 and the carriage height settingmechanism 20 can be employed to produce a planed workpiece having athickness that is equal to the height marking 930 that has beenselected.

An alternately constructed carriage height setting mechanism 20′ isillustrated in FIG. 21 a. The carriage height setting mechanism 20′ issimilar to the carriage height setting mechanism 20, except that thestop member 902 is replaced by a stop mechanism 902′. The stop mechanism902′ includes a bushing 902 a and a set of pins 902 b. The bushing 902 ais coupled to the base 14 in a manner similar to that of the stop member902 (i.e., threadably engaged to the base 14, with its height beingadjusted through a jam nut 946). The bushing 902 a includes aninternally threaded hole 902 c and defines a lower datum 902 d. Each ofthe pins in the set of pins 902 b includes a threaded post 902 e that issized to threadably engage the internally threaded hole 902 c, and abody 902 f that extends upwardly of a upper datum 902 g. Each of thepins that comprise the set of pins 902 b are differently sized, varyingin the example provided by one inch.

In operation, the user of the planer 10 selects pin that would cooperatewith the stop adjustment assembly 900 (FIG. 19) to provide a range ofcarriage heights that include a height dimension to which the carriage12 is to be lowered. The pin would then be threadably coupled to thebushing 902 a such that the upper datum 902 g was in contact with thelower datum 902 d. If it is subsequently necessary to change the heightof the carriage 12 to a height that is not within the range that isprovided by the pin and the stop adjustment assembly 900, another pinmay be substituted for the pin that is engaged to the bushing 902 a, oralternatively, the pin may be removed altogether from the bushing 902 a.In this regard, the stop adjustment assembly 900 may be brought directlyinto contact with the lower datum 902 d.

Height Scale Mechanism

With reference to FIGS. 2 and 22 through 24, the height scale mechanism22 is illustrated to include a housing 1000, a rotary scale 1002, apointer 1004, an engagement member 1006, a coupler 1008, an annularplate 1010, a torsion spring 1012 and a tension wheel 1014. The housing1000 is illustrated to be formed by a pair of housing halves 1016 and1018 which are injected molded from a thermoplastic resin and whichcollectively define a scale cavity 1020 and a pointer aperture 1022.Each housing half 1016 and 1018 includes a scale shaft aperture 1024 anda plurality of mounting bosses 1026 which permit the housing halves 1016and 1018 to be secured to one another and to the carriage 40 viaconventional threaded fasteners 1028.

The rotary scale 1002 includes first and second drum portions 1030 and1032, respectively, and a scale shaft 1034. The first drum portion 1030is cylindrically shaped, having first and second scales 1036 and 1038,respectively, each of which including a plurality of premarked heightindications 1040. In the example provided, the first scale 1036 providesheight indications 1040 that are spaced apart by a first predeterminedinterval, ¼ inch for example, and the second scale provides heightindications 1040 that are spaced apart by a second predeterminedinterval that is relatively smaller than the first predeterminedinterval, {fraction (1/32)} inch for example. Those skilled in the artwill understand, however, that the first and second scales 1036 and 1038may alternatively be have height indications 1040 corresponding to twodifferent measuring systems, such as inches and millimeters.

The second drum portion 1032 is also cylindrically shaped and is fixedlycoupled to the first drum portion 1030 such that their rotational axesare coincident. The second drum portion 1032 includes an attachmentfeature, such as a slot 1042, that permits a first end 1044 of theengagement member 1006, which is illustrated to be a wire in the exampleprovided, to be fixedly coupled to the outer perimeter of the seconddrum portion 1032 in a predetermined radial position. The annular plate1010 is fixedly coupled to the end of the second drum portion 1032opposite the first drum portion 1030, creating a U-shaped annularchannel 1048. The engagement member 1006 is wrapped around the outercircumference of the second drum portion 1032 and lies in the U-shapedannular channel 1048.

The scale shaft 1034 is cylindrically shaped and extends through thefirst and second drum portions 1030 and 1032. The axis 1050 of the scaleshaft 1034 is located coincident with the rotational axes of the firstand second drum portions 1030 and 1032. The portion of the scale shaft1034 that extends outwardly from the second drum portion 1032 includes aslotted spring tab aperture 1052 and a knurled end portion 1054, both ofwhich will be discussed in greater detail, below.

The rotary scale 1002 is positioned in the housing 1000 such that thescale shaft 1034 extends into the scale shaft apertures 1024 in housinghalves 1016 and 1018 and the first and second drum portions 1030 and1032 are supported for rotation in the scale cavity 1020. The pointer1004, which is illustrated to be a formed from a clear plastic material,is sized to engage the housing halves 1016 and 1018 and cover thepointer aperture 1022 to thereby permit the operator of the planermechanism 10 to read the first and second scales 1036 and 1038 on thefirst drum portion 1030. The pointer 1004 includes a reference mark1060, which is illustrated to be a relatively thin red line that crossesthe length of the pointer 1004, to permit the operator to accuratelyread the first and second scales 1036 and 1038 and identify theparticular height indication 1040 which corresponds to the height of theplaner carriage assembly 12 relative to the planing surface 370. Theengagement member 1006 extends out a hole 1062 in the bottom surface1064 of the housing 1000 and thereafter, the housing halves 1016 and1018 are coupled together.

The engagement member 1006 is fed through a corresponding hole 1066 inthe carriage 40. Thereafter, the housing 1000 is coupled to the carriage40 and the second end of the engagement member 1006 is pulled throughthe carriage 40 and coupled to the coupler 1008 that is fixedly coupledto the base structure 310. In the particular example provided, thecoupler 1008 includes a first portion 1070, which is fixedly attached tothe base structure 310, and a second portion 1072 which is coupled tothe first portion 1070 but rotatable relative to the base structure 310.The distal end of the second portion 1072 is illustrated to include athreaded aperture 1074 which is sized to threadably engage a threadedcoupling 1076 that is fixed to the second end of the engagement member1006. Adjustment of the position of the engagement member 1006 isaccomplished by controlling the amount by which the threaded coupling1076 is engaged into the threaded aperture 1074. A jam nut 1078 isemployed to fix the location of the second end of the engagement member1006 relative to the base structure 310.

The torsion spring 1012 is illustrated to be a conventional a coiled,flat band spring of the type that are commonly employed withspring-retracting measuring tapes (tape measurers) and includes a firstretaining tab 1080, which is formed into a first end of the flat band1082, and a second retaining tab 1084, which is formed into the oppositeend of the flat band 1082. The first retaining tab 1080 extends radiallythrough an axis about which the flat band 1082 is coiled. The secondretaining tab 1084 extends radially outwardly from the coiled band 1082.The torsion spring 1012 is mounted to the portion of the scale shaft1034 that extends outwardly beyond the housing half 1018 such that thefirst retaining tab 1080 is disposed within the slotted spring tabaperture 1052.

The tension wheel 1014 is illustrated to include a hollow cylindricaladjustment knob 1086 and a mounting flange 1088. With additionalreference to FIG. 25, the adjustment knob 1086 defines a hollow cavity1090, which is sized to receive the torsion spring 1012 and a radiallyoutwardly extending slot 1092, which is sized to receive the secondretaining tab 1084. The mounting flange 1088 extends radially outwardlyof the adjustment knob 1086 and includes a plurality of mounting slots1094 which permit the tension wheel 1014 to be coupled to the outersurface 1096 of the housing half 1018 via a pair of conventional screws1098.

The mounting slots 1094 permit the tension wheel 1014 to be rotatedrelative to the housing 1000 when the screws 1098 are loosened somewhatto permit the rotational position of the slot 1092 to be adjustedrelative to the housing 1000 to thereby ensure that the torsion spring1012 applies an appropriate level of torsion to the scale shaft 1034.Torsion applied to the scale shaft 1034 biases the rotary scale 1002 ina direction that tends to winds the engagement member 1006 onto thesecond drum portion 1032 of the rotary scale 1002. The rotatable natureof the tension wheel 1014 relative to the housing 1000 may also be usedto change the relative position of the rotary scale 1002 relative to thehousing 1000.

As the engagement member 1006 is coupled to both the rotary scale 1002and the base structure 310, and as the torsion spring 1012 exerts abiasing force to the rotary scale 1002 which maintains tension in theengagement member 1006, movement of the planer carriage assembly 12 inthe vertical direction will cause corresponding rotation of the rotaryscale 1002. Controlled rotation of the rotary scale 1002 in relation tothe vertical travel of the planer carriage assembly 12 is achievedthrough the dimensioning of the second drum portion 1032. Morespecifically, the circumference of the second drum portion 1032 is sizedto correspond to the maximum vertical distance that the planer carriageassembly 12 can move relative to the planing surface 370. For example,if the maximum vertical distance that the planer carriage assembly 12can move relative to the planing surface 370 is 6 inches, thecircumference (C) of the second drum portion 1032 is set equal to 6inches and the equation C=π×d is employed to solve for the diameter (d)of the second drum portion 1032. In this example, the diameter (d) ofthe second drum portion 1032 is about 1.9099 inches.

In contrast to the diameter of the second drum portion 1032, thediameter of the first drum portion 1030 is selected on the basis ofseveral different factors, including a desired degree of magnificationand the capability of the rotary scale 1002 to be packaged into theplaner mechanism 10. As those skilled in the art will understand,magnification is accomplished by sizing the diameter of the first drumportion 1030 larger than the diameter of the second drum portion 1032.

The placement of the first and second scales 1036 and 1038 on the firstdrum portion 1030 is also achieved with reference to the maximumvertical distance that the planer carriage assembly 12 can move relativeto the planing surface 370. In the example provided, the first scale1036 includes height indications 1040 at every ¼ inch, the second scale1038 includes height indications 1040 at every {fraction (1/32)} inchand the maximum vertical distance that the planer carriage assembly 12can move relative to the planing surface 370 is 6 inches. Accordingly,the first scale includes 24 evenly spaced height indications 1040 (i.e.,15° apart) and the second scale 1038 includes 192 evenly spaced heightindications 1040 (1.875° apart) around the circumference of the firstdrum portion 1030.

As those skilled in the art will understand, the height scale mechanism22 must be calibrated prior to its use to ensure that the heightdimension that is indicated by the first and second scales 1036 and 1038corresponds to the actual height at which the knife edge 754 of thecutter blades 704 are positioned above the planing surface 370. Thoseskilled in the art will readily understand that the calibration processis substantially similar to that described for the calibration of thecarriage height setting mechanism 20 described above. Briefly, aworkpiece is initially planed and its thickness is then measured. Thethickness of the workpiece is next compared to the height dimension thatis indicated by the first and second scales 1036 and 1038 and the amountby which the threaded coupling 1076 is engaged into the threadedaperture 1074 is adjusted as necessary to align the reference mark 1060on the pointer 1004 to the appropriate height indications 1040 on thefirst and second scales 1036 and 1038.

Although the height scale mechanism 22 of the present invention has beenillustrated as having an engagement member 1006 that has been formedfrom a wire, those skilled in the art will understand that the heightscale mechanism may be constructed somewhat differently. For example,the engagement member may be a rigid rack 1006′, as illustrated in FIG.25 a, having a plurality of gear teeth 1006 a that meshingly engage aplurality of gear teeth 1006 b that are formed into the outercircumference of the second drum portion 1032. This modification wouldeliminate the need for the annular plate 1010, the torsion spring 1012and the tension wheel 1014 and would also require modifications to thecoupler 1008 that would permit the engagement member 1006 to maintainengaged with the gear teeth on the second drum portion 1032 while thecoupler 1008 is being adjusted.

Material Removal Gauge

With reference to FIGS. 2, 26 and 27, the material removal gauge 24 isillustrated to include a follower assembly 1100, a pointer assembly 1102and a pointer housing 1104. The follower assembly 1100 is illustrated toinclude a bushing 1106, a lock screw 1108, a post 1110, a shoulder screw1112, a roller 1114, an adjustment rod 1116, and a nut 1118. In theexample provided, the bushing 1106 is illustrated to be a conventionalheaded, slip-fit, replaceable bushing, such as those that arecommercially available from the Carr-Lane Manufacturing Company. Thebushing 1106 has a body 1120 with an outer diameter that is sized toslip fit into a bushing aperture 1122 that is formed in the carriage 40forwardly of the cutter pocket 54 and proximate the forward edge 1124 ofthe carriage 40. The axis of the bushing aperture 1122 is alignedgenerally parallel the axes of the nut apertures 60 that are formed inthe carriage 40. The bushing 1106 also includes a head 1126, which issized relatively larger than the bushing aperture 1122 and into which aconventional lock screw recess 1128 is formed, as well as a D-shapedbushing bore 1130 that extends completely through the bushing 1106.

A commercially available lock screw 1108 having a threaded portion 1132,a cylindrical body portion 1134 and a head portion 1136 is employed toretain the bushing 1106 to the carriage 40 in a conventional manner thatneed not be discussed in detail. Briefly, the body 1120 of the bushing1106 is placed in the bushing aperture 1122, the head 1126 of thebushing 1106 is abutted against the top surface 64 of the carriage 40and the bushing 1106 is rotated to align the lock screw recess 1128 witha threaded lock screw mounting aperture (not specifically shown) formedinto the carriage 40. The threaded portion 1132 of the lock screw 1108is threadably engaged to the lock screw mounting aperture such that thehead portion 1136 of the lock screw 1108 exerts a clamping force ontothe head 1126 of the bushing 1106 which retains it in the carriage 40.The body portion 1134 of the lock screw 1108 is disposed within the lockscrew recess 1128 and prevents the bushing 1106 from rotating in thebushing aperture 1122. Those skilled in the art will understand thatother types of commercially available bushings may be substituted forthe bushing 1106 and lock screw 1108 illustrated, including a press-fitheaded and headless bushings and press-fit serrated bushings.

The post 1110 is illustrated to have a D-shaped body 1140, which issized to slip-fit in the bushing bore 1130, a post head 1142, which iscoupled to a first end of the body 1140, a roller mounting flange 1144,which is coupled to the opposite end of the body 1140, and a threadedaperture 1146 is formed through the post head 1142 and into the body1140. The post head 1142 is sized generally larger than the body 1140 toprevent the post 1110 from sliding downwardly out of the bushing bore1130. The roller mounting flange 1144 is a “flat” that has been machinedonto the end of the body 1140 such that when a face 1148 of the roller1114 is abutted against the mounting surface 1150 of the roller mountingflange 1144, the vertical centerline 1152 of the roller 1114 iscoincident with the centerline 1154 of the post 1110. The rollermounting flange 1144 includes a threaded aperture 1156 which is sized tothreadably engage the threaded portion 1158 of the shoulder screw 1112.

The roller 1114 is generally cylindrically shaped, having a mountingaperture 1160 that is sized to receive the body 1162 of the shoulderscrew 1112. The shoulder screw 1112 is placed through the roller 1114and threadably engaged to the threaded aperture 1156 of the rollermounting flange 1144 to thereby journally support the roller 1114 forrotation about an axis that is generally perpendicular to the axis ofthe post 1110.

The adjustment rod 1116 is a cylindrically shaped post, having a contacttip 1164, which is configured to contact a portion of the pointerassembly 1102, and a threaded body 1166 that is sized to threadablyengage the nut 1118 and the threaded aperture 1146 that is formed intothe end of the post 1110. Calibration of the material removal gauge 24is accomplished by rotating the adjustment rod 1116 within the threadedaperture 1146 and fixing the relationship of the adjustment rod 1116 andpost 1110 by tightening the nut 1118 against the post head 1142. Theprocess through which the material removal gauge 24 is calibrated willbe discussed in more detail, below.

The pointer assembly 1102 is illustrated to include a unitarily formedpointer 1170 and a shaft 1172 that supports the pointer 1170 forrotation in the pointer housing 1104. The pointer 1170 includes a scalestructure 1174 and a lever 1176. The scale structure 1174 includes amounting aperture 1178 through which the shaft 1172 is disposed, and ascale surface 1180 which conforms to a predetermined radius that iscentered at the center of the mounting aperture 1178. The scale surface1180 includes a plurality of height indications 1182 that may beengraved, printed, silk screened, hot-stamped, embossed, molded onto orotherwise permanently marked or attached thereto. The lever 1176 isfixedly coupled to the scale structure 1174 and includes a contactmember 1184 that is configured to contact the upper surface 1186 of aworkpiece 300 (FIG. 1) that is being pushed into the planer mechanism10. The contact member 1184 is preferably disposed radially outwardlyfrom the center of the mounting aperture 1178 by a distance which isrelatively smaller than the distance between the center of the mountingaperture 1178 and the scale surface 1180 so as to provide the materialremoval gauge 24 with a desired degree of magnification in a manner thatis similar to the magnification that is achieved by the height scalemechanism 22.

The magnification effect is illustrated in FIGS. 28 and 29. In FIG. 28,the contact member 1184 and the scale surface 1180 are disposed radiallyoutwardly from the center of the mounting aperture 1178 by a commondistance. A vertical displacement of the contact member 1184 by adistance Δh causes the scale surface 1180 to rotate through an anglehaving a magnitude of α1. In contrast, when the scale surface 1180 isdisposed radially outwardly of the contact member 1184 as illustrated inFIG. 29, the vertical displacement of the contact member 1184 by thedistance Δh causes the scale surface 1180 to rotate through an anglehaving a magnitude of α2, which is illustrated to be substantiallylarger than α1. As such, the height indications 1182 on the scalesurface 1180 of the pointer 1170 that is illustrated in FIG. 29 arespaced relatively further apart as compared to the height indications1182 on the pointer 1170 that is illustrated in FIG. 28. As such, theembodiment illustrated in FIG. 29 may be read with a higher degree ofaccuracy.

Referring back to FIGS. 2, 26 and 27, and with additional reference toFIG. 30, the pointer housing 1104 includes a shaft aperture 1190, whichis sized to receive the shaft 1172, a pointer aperture 1192, which issized to permit the pointer 1170 to rotate therein through apredetermined included angle, a scale window 1194 and a plurality ofmounting lugs 1196 that permit the pointer housing 1104 to be fixedlycoupled to the carriage 40. The scale window 1194 is disposed in closeproximity with the scale surface 1180 to minimize parallax and includesa reference datum 1198, such as a thin red horizontal line, whichpermits the operator of the planer mechanism 10 to accurately read thescale surface 1180.

As mentioned above, calibration of the pointer 1170 is necessary priorto the use of the material removal gauge 24. This is accomplished byadjusting the effective height of the follower assembly 1100 until theamount of material that is removed from a workpiece 300 during theplaning operation is consistent with the reading of the scale surface1180 of the pointer 1170. As discussed above, the effective height ofthe follower assembly 1100 is adjusted by rotating the adjustment rod1116 within the threaded aperture 1146. Once the height indication 1182on the scale surface 1180 of the pointer 1170 is consistent with theamount of material that is being remove, the material removal gauge 24has been calibrated.

While the material removal gauge 24 has been illustrated with aunitarily formed pointer 1170 having a lever 1176 with a contact member1184 that directly contacts a workpiece 300, those skilled in the artwill appreciate, however, that the pointer may be constructed somewhatdifferently. For example, a spacing rod 1200 may be used in conjunctionwith the pointer 1170 as illustrated in FIG. 31 to permit the locationof the scale window 1194 and scale surface 1180 to be raised relative tothe carriage 40 so that the operator may identify the particular heightindication 1182 that is aligned to the reference datum 1198 withoutbending over. In addition to improving the ergonomics of the planermechanism 10, the elevating of the scale window 1194 and scale surface1180 enables the scale surface 1180 to be read more easily, therebyimproving the accuracy of the material removal gauge 24.

Dust Collection System Having Dual-Sided Fan

In FIGS. 2, 3, 3 a, 32 and 33, the dust collection system 26 isillustrated to include a dust hood 870, a volute housing 1210 and aimpeller structure 1212. In the example illustrated, the dust hood 870includes a body portion 1220 and a ducting portion 1222 and ispreferably unitarily formed in a plastic injection molding process. Thebody portion 1220 is defined by a pair of angled side wall members 1224and a pair of end wall members 1226 that collectively cooperate toprovide the body portion 1220 with a shape that is similar to that of aright triangular prism. The size the body portion 1220 is such that itcompletely covers the cutter pocket 54 that is formed in the carriage40. Mounting lugs 1228 extend outwardly from the side and end wallmembers 1224 and 1226 and permit the body portion 1220 to be fixedlycoupled to the carriage 40. Optionally, a gasket (not shown) may beplaced between the carriage 40 and the body portion 1220 to seal thejoint that is formed therebetween.

The ducting portion 1222 is fixedly coupled to the forward side wallmember 1224 of the body portion 1220, extending forwardly therefrom andterminating at a coupling portion 1230 that is configured to mate to thevolute housing 1210. The coupling portion 1230 includes a circular ductaperture 1232 but is otherwise completely enclosed. Optionally, a collargasket (not shown), which is formed from a resilient material, such asrubber or neoprene, may be employed to seal the joint between thecoupling portion 1230 and the volute housing 1210. The collar gasket mayinclude a central aperture and a pair of spaced apart wall members thatcooperate to define a U-shaped annular recess that is concentric to thecentral aperture. The U-shaped annular recess is configured such thateach wall member sealingly engages an opposite side of the wall 1242 ofthe coupling portion 1230 into which the duct aperture 1232 is formedand the base of the annular recess sealingly engages the perimeter ofthe duct aperture 1232.

The volute housing 1210 is illustrated to be formed from a pair ofmating volute halves 1210 a and 1210 b which cooperate to define ascroll-shaped central cavity 1250 having a tongue portion 1252, a throatportion 1254, an outlet port 1256 and a pair of inlet apertures 1258 aand 1258 b. The central cavity 1250 gradually increases in itscross-sectional area from the tongue portion 1252 to the throat portion1254 in a manner that is known in the art and beyond the scope of thepresent disclosure. The volute housing 1210 is fixedly but removablycoupled to the housing end cap 90 of the motor assembly 42 via aplurality of threaded fasteners 1260.

The impeller structure 1212 is illustrated to include a central flangeportion 1262, a first set of impeller blades 1264 and a second set ofimpeller blades 1266. The central flange portion 1262 includes amounting aperture 1268, which is sized to fit over the second endportion 114 of the shaft 110 of the rotor 88, and a dividing flange 1270that separates the first and second sets of impeller blades 1264 and1266. The mounting aperture 1268 includes a pair of parallel sidewalls1272 that are configured to engage the parallel flats 124 to inhibitrelative rotation between the shaft 110 and the impeller structure 1212.A washer (not shown) and a nut (not shown), which is sized to threadablyengage the threaded end portion 126 of the second end portion 114 of theshaft 110, are employed to fixedly but removably couple the impellerstructure 1212 to the shaft 110. Each of the first and second sets ofimpeller blades 1264 and 1266 are arranged generally perpendicular tothe dividing flange 1270 and extend radially outwardly from the centralflange portion 1262.

The first set of impeller blades 1264 are configured to draw air throughthe housing shell 84 to cool the motor assembly 42 during the operationof the planer mechanism 10. More specifically, rotation of the impellerstructure 1212 in the volute housing 1210 generates a negative pressuredifferential that causes air to enter into the plurality of air inletapertures 100 in the housing shell 84, travel through housing shell 84drawing heat away from the components of the motor assembly 42 and exitthe housing end cap 90 via the plurality of cooling vents 108.Thereafter, the heated air exiting the motor assembly 42 is directedinto the inlet aperture 1258 a in the volute housing 1210 where therotating blades of the first set of impeller blades 1264 transferadditional energy into the air before it is expelled from the outletport 1256 of the volute housing 1210.

The second set of impeller blades 1266 are configured to draw the dustchips 1280 that are generated during the operation of the planermechanism 10 through the volute housing 1210. More specifically,rotation of the impeller structure 1212 in the volute housing 1210generates a negative pressure differential that causes air to be drawnfrom around the workpiece 300 (FIG. 1), through the cutter pocket 54 ofthe carriage 40, through the dust hood 870 and into the inlet aperture1258 b of the volute housing 1210. The air-borne chips 1280 in thecutter pocket 54 are carried away by the air that is being drawn intothe inlet aperture 1258 b of the volute housing 1210, therebyfacilitating the collection of the chips 1280. Those skilled in the artwill appreciate that a suitable chip collection mechanism, such as a bagthat is constructed from fine mesh, may be coupled to the outlet port1256 to capture the chips 1280 that are blown out of the volute housing1210. The dividing flange 1270 that is disposed between the first andsecond sets of impeller blades 1264 and 1266 ensures that the chips 1280that are entering the volute housing 1210 will not be discharged in anaxial direction against the housing end cap 90, thus ensuring that thechips 1280 do not inhibit the cooling or operation of the motor assembly42.

Construction of the dust collection system 26 in this manner is highlyadvantageous in that a single motor can be used for operating both thecutterhead assembly 50 and the fan that facilitates the removal andcollection of the wood chips 1280 that are generated during theoperation of the planer mechanism 10. While the dust collection system26 has been illustrated in conjunction with a planing apparatus, thoseskilled in the art will appreciate, however, that the dust collectionapparatus may also be employed in conjunction with various otherelectric power tools, including for example, saws with a rotating blade,saws with a reciprocating blade, band saws, jointers, routers, laythes,drill presses, shapers, sanders and mortisers.

Power Take-Off Mechanism

With reference to FIGS. 2, 4, 4 b and 34, the power take-off mechanism28 is illustrated to include a power input portion 1300, which receivesa rotational input from the gearbox 44, and a power output portion 1302,which transmits a power output to the planer carriage elevationmechanism 16 for selectively moving the carriage assembly 12 in avertical direction under a source of power.

The power input portion 1300 is illustrated to include a support plate1310, a shaft bushing 1312, a first gear 1314, a second gear 1316, athird gear 1318, a selector lever 1320, a support plate biasing spring1322 and a hand wheel biasing spring 1324. The support plate 1310 isillustrated to be generally T-shaped, having a first arm portion 1326, asecond arm portion 1328 and a third arm portion 1330. The first armportion 1326 terminates at its distal end at a mounting flange 1332 thatincludes a bushing aperture 1334 and a pair of threaded apertures (notspecifically shown). The bushing aperture 1334 is sized to engage theouter diameter of the shaft bushing 1312 in a press-fit manner. Theshaft bushing 1312 includes a shaft bore 1340 having an inside diameterthat is configured to rotatably fit onto the shaft portion 250 of thefirst reducing gear 204. Each of the threaded apertures is sized toreceive a shoulder bolt 1342 having a cylindrically-shaped body portion1344. The second arm portion 1328 terminates at its distal end at anaperture 1346 which is configured to receive the screw 1348 that fixedlycoupled the selector lever 1320 to the support plate 1310. The third armportion 1330 extends downwardly from the second arm portion 1328 andcurves inwardly toward the first arm portion 1326. The third arm portion1330 includes an arcuate slot 1350 having a concentric side walls 1352and 1354 and a countersunk portion 1356 that is disposed in the centerof the arcuate slot 1350.

The first gear 1314 is includes a plurality of first gear teeth 1360 andis coupled for rotation with the shaft portion 250 of the first reducinggear 204. A first one of the shoulder bolts 1342 is threadably engagedto a threaded aperture in the mounting flange 1332 and rotatablysupports the second gear 1316. The second gear 1316 includes a pluralityof second gear teeth 1362 that are meshingly engaged with the first gearteeth 1360. The second one of the shoulder bolts 1342 is threadablyengaged to another one of the threaded apertures in the mounting flange1332 and rotatably supports the third gear 1318. The third gear 1318includes a plurality of third gear teeth 1364 that are meshingly engagedwith the second gear teeth 1362.

With additional reference to FIG. 8, the front axle 500 is shown toextend through the arcuate slot 1350 in the third arm portion 1330 andterminate at an axle end 1370 having a drive portion 1372 having anon-circular cross-section, an idler portion 1374 having a circularcross-section and a threaded end 1376. The hand wheel 510 includes acoupling aperture 1378, having a geometry that mates to the geometry ofthe drive portion 1372 and a cam portion 1380, having a frusto-conicalshape. The hand wheel 510 is slidable on the axle end 1370 between anengaged portion, wherein the drive portion 1372 is matingly engaged toand coupled for rotation with the hand wheel 510, and a disengagedportion, wherein the idler portion 1374 is aligned to the couplingaperture 1378 to thereby permit the front axle 500 and hand wheel 510 torotate independently of one another. The hand wheel biasing spring 1324is employed to generate a spring force that biases the hand wheel 510toward the drive portion 1372 to thereby engage the frusto-conical shapeof cam portion 1380 to the countersunk portion 1356 in the arcuate slot1350. Engagement of the cam portion 1380 to the countersunk portion 1356operates to fix the support plate 1310 relative to the rotational axisof the hand wheel 510. The support plate biasing spring 1322 is atorsion spring that is employed to exert a biasing force onto the firstarm portion 1326 of the support plate 1310 when the front axle 500 islocated in the proximal portion 1382 of the arcuate slot 1350.

The power output portion 1302 is illustrated to have a shaft 1400, agear 1402, first and second pulleys 1404 and 1406, respectively, and abelt 1408. The shaft 1400 extends through an auxiliary output aperture1410 formed into the gearbox housing 200 and is journally supported forrotation by a shaft support boss 240, which is formed into one of thegearbox housing halves 230, and a bushing 1412 that is fixed to theother gearbox housing half 230. The gear 1402 and the first pulley 1404are coupled for rotation with the shaft 1400. The second pulley 1406 iscoupled for rotation with the rear axle 502. The belt 1408 rotatablycouples the first and second pulleys 1404 and 1406.

During the operation of the planer mechanism 10, the support platebiasing spring 1322 and the hand wheel biasing spring 1324 cooperate tobias the support plate 1310 into a neutral position that is illustratedin FIG. 35, wherein the cam portion 1380 of the hand wheel 510 isengaged to the countersunk portion 1356 of the arcuate slot 1350. As thefirst gear 1314 is coupled for rotation with the shaft portion 250 ofthe first reducing gear 204, the first gear 1314 will rotate (wheneverthe cutter head 702 is rotating) and cause the second and third gears1316 and 1318 to rotate. However, when the support plate 1310 ispositioned in the neutral position, neither the second nor third gears1316 and 1318 meshingly engage the gear 1402 and as such, the firstpulley 1404 does not rotate.

When it is necessary to move the carriage assembly 12 in a verticaldirection by a significant distance, the power take-off mechanism 28 maybe employed to move the carriage assembly 12 under a source of power. Ifthe carriage assembly 12 is to be moved upward relative to the planingsurface 370, the selector lever 1320 is rotated upwardly as illustratedin FIG. 36. With the upward rotation of the selector lever 1320, the camportion 1380 of the hand wheel 510 is forced out of the countersunkportion 1356 of the arcuate slot 1350, moving the hand wheel 510 inaxially on the front axle 500 from the engaged position to thedisengaged position, so that the cam portion 1380 abuts the outsidesurface 1414 of the third arm portion 1330.

As the selector lever 1320 is fixedly coupled to the support plate 1310,upward motion of the selector lever 1320 also causes the support plateto rotate about the shaft portion 250 and permit the second gear 1316 tomeshingly engage the gear 1402 of the power output portion 1302.Rotational power received by the gear 1402 is transmitted through theshaft 1400 to the first pulley 1404 and thereafter through the belt 1408to the second pulley 1406. As the rear axle 502 is coupled to the frontaxle 500 via the pulleys 506 and the belt 508, rotation of the secondpulley 1406 will cause the front and rear axles 500 and 502 to rotate tothereby rotate the lower lock nuts 432 on the adjustment portion 412 ofthe guide posts 400 to cause the carriage assembly 12 to travel upwardlyon the guide posts 400. However, as the idler portion 1374 and couplingaperture 1378 are aligned to one another, the hand wheel 510 isrotationally disconnected from the front axle 500, permitting the frontaxle 500 to rotate freely without causing similar rotation of the handwheel 510.

When the carriage assembly 12 is positioned in a desired manner, theselector lever 1320 is released to permit the support plate biasingspring 1322 to rotate the support plate 1310 downwardly. Thereafter, thehand wheel biasing spring 1324 forces the hand wheel 510 inwardly towardthe support plate 1310 to engage the cam portion 1380 to the countersunkportion 1356 of the arcuate slot 1350. The axial movement of the handwheel 510 toward the support plate 1310 also serves to re-couple thecoupling aperture 1378 to the drive portion 1372 to thereby rotatablycouple the hand wheel 510 and the front axle 500.

Similarly, if the carriage assembly 12 is to be moved downward relativeto the planing surface 370, the selector lever 1320 is rotateddownwardly as illustrated in FIG. 37. With the downward rotation of theselector lever 1320, the cam portion 1380 of the hand wheel 510 isforced out of the countersunk portion 1356 of the arcuate slot 1350,moving the hand wheel 510 in axially on the front axle 500 from theengaged position to the disengaged position so as to disconnect the handwheel 510 from the front axle 500 as described above.

As the selector lever 1320 is fixedly coupled to the support plate 1310,upward motion of the selector lever 1320 also causes the support plateto rotate about the shaft portion 250 and permit the third gear 1318 tomeshingly engage the gear 1402 of the power output portion 1302. Asthose skilled in the art will readily understand, the selectiveengagement of the second and third gears 1316 and 1318 is employed tochange the rotational direction of the input to the gear 1402. Asmentioned above, rotational power received by the gear 1402 istransmitted through the shaft 1400 to the first pulley 1404 andthereafter through the belt 1408 to the second pulley 1406 to therebyprovide the adjustment mechanism 404 with a source of power for rotatingthe lower lock nuts 432. When the carriage assembly 12 is positioned ina desired manner, the selector lever 1320 is lifted to disengage thethird gear 1318 from the gear 1402 and permit the hand wheel biasingspring 1324 to force the hand wheel 510 inwardly toward the supportplate 1310 to engage the cam portion 1380 to the countersunk portion1356 of the arcuate slot 1350. As mentioned above, the axial movement ofthe hand wheel 510 toward the support plate 1310 also serves tore-couple the coupling aperture 1378 to the drive portion 1372 tothereby rotatably couple the hand wheel 510 and the front axle 500.

While the power take-off mechanism 28 has been illustrated as includinga pair of meshing gears, each of which being selectively engagable witha gear on the power output portion 1302, those skilled in the art willunderstand that the power take-off mechanism may be constructed somewhatdifferently. For example, a first combination gear and pulley 1500, asecond combination gear and pulley 1502 and a belt 1504 may besubstituted for the second and third gears 1316 and 1318 and the gear1402 as illustrated in FIGS. 38 through 40. In this example, rotation ofthe support plate 1310 in the upward direction (FIG. 39) engages thegear teeth 1510 of the first combination gear and pulley 1500 to thegear teeth 1512 of the second combination gear and pulley 1502 in amanner that is substantially identical to that described above. In thiscondition, as well as when the support plate 1310 is positioned in theneutral position, the belt 1504 is disposed around a pulley portion 1514of both of the first and second combination gear and pulley 1500 and1502 and as such, the belt 1504 does not rotate, let alone transmit anyrotational power.

Rotation of the support plate 1310 in the downward direction (FIG. 40),however, causes the pulley portions 1514 of the first and secondcombination gear and pulley 1500 and 1502 to apply tension to the belt1504, permitting the belt 1504 to transmit rotational power from thefirst combination gear and pulley 1500 to the second combination gearand pulley 1502. When the first and second combination gear and pulley1500 and 1502 are coupled via the belt 1504, they rotate in the samerotational direction, whereas when the first and second combination gearand pulley 1500 and 1502 are coupled via the gear teeth 1510 and 1512,they rotate in opposite rotational directions.

While the invention has been described in the specification andillustrated in the drawings with reference to a preferred embodiment, itwill be understood by those skilled in the art that various changes maybe made and equivalents may be substituted for elements thereof withoutdeparting from the scope of the invention as defined in the claims. Inaddition, many modifications may be made to adapt a particular situationor material to the teachings of the invention without departing from theessential scope thereof. Therefore, it is intended that the inventionnot be limited to the particular embodiment illustrated by the drawingsand described in the specification as the best mode presentlycontemplated for carrying out this invention, but that the inventionwill include any embodiments falling within the foregoing descriptionand the appended claims.

1. A method comprising: forming a base structure with a body portionthat defines a support surface; forming a plate structure; coupling theplate structure to the base structure; and machining the plate structureto define a flat reference surface only after the plate structure andthe base structure have been coupled to one another; wherein the supportsurface is not machined prior to the coupling of the plate structure andthe base structure.
 2. The method of claim 1, wherein coupling the platestructure to the base structure comprises: inserting a threaded fastenerthrough the body portion; and threadably engaging the threaded fastenerto the plate structure.
 3. The method of claim 2, wherein the platestructure includes a boss that extends away from the flat referencesurface.
 4. The method of claim 3, wherein the boss is received into amounting aperture formed in the body portion.
 5. The method of claim 1,wherein coupling the plate structure to the base structure comprises:forming a hole in the plate structure; forming a hole in the bodyportion that is arranged generally transverse to the support surface;and inserting a threaded fastener through the hole in the platestructure and the hole in the body portion.
 6. The method of claim 5,wherein the hole in the plate structure and the threaded fastenercooperate to locate the plate structure relative to the body.
 7. Themethod of claim 6, wherein the hole in the plate structure includes acountersunk portion and wherein the threaded fastener includes a conicalportion that matingly engages the countersunk portion.
 8. The method ofclaim 1, further comprising forming a plurality of guide post mountingapertures into the base structure.
 9. The method of claim 8, wherein theguide post mounting apertures are formed into the base structure afterthe plate structure is coupled to the base structure.
 10. The method ofclaim 1, wherein the power tool is a planer.
 11. The method of claim 1,wherein the base structure is formed of a first material and the platestructure is formed of a second material that is different than thefirst material.
 12. The method of claim 11, wherein the first materialis aluminum or magnesium and the second material is iron.
 13. The methodof claim 1, wherein the base portion of the base structure includes aplurality of webs that cooperate to defines a plurality of void spaces,the void spaces being disposed beneath the plate structure when the basestructure and the plate structure are coupled to one another.
 14. Apower tool comprising a base assembly having a base structure and aplate structure, the base structure being formed of a first material andhaving a body portion that defines a support surface, the platestructure being formed of a second material, the plate structure beingcoupled to the base structure in abutment with the support surface,wherein the support surface is not machined prior to the coupling of theplate structure and the base structure and wherein the base assembly ismachined to generate a flat reference surface only after the platestructure and the base structure have been coupled to one another. 15.The power tool of claim 14, wherein a plurality of guide post mountingapertures are formed in the base assembly and wherein the power toolfurther comprises a plurality of guide posts disposed in the guide postmounting apertures.
 16. The power tool of claim 15, wherein the guideposts are fixedly coupled to the base assembly.
 17. The power tool ofclaim 14, further comprising a carriage movably coupled to the baseassembly and a rotating cutter coupled to the carriage.
 18. A methodcomprising: forming a base assembly with a first portion and a secondportion, the first portion being formed of cast aluminum or magnesiumand defining a bottom surface and an upper surface, the second portionbeing formed of cast iron and including a cast lower surface and a castupper surface, the cast lower surface being abutted against the uppersurface of the first portion; fixturing the base assembly to a machinetool; machining the second portion to define a reference surface that isgenerally parallel with a plane on which the lower surface of the firstportion rests.
 19. The method of claim 18, further comprising: forming aplurality of guide post mounting apertures into the base assembly; andunfixturing the base assembly from the machine tool only after the guidepost mounting apertures have been formed and the second portion has beenmachined to define the reference surface.
 20. The method of claim 18,wherein forming the base assembly includes clamping the first and secondportions to one another with a plurality of threaded fasteners.